diff --git a/src/OpenMesh/Core/Mesh/PolyMeshT.hh b/src/OpenMesh/Core/Mesh/PolyMeshT.hh
index 113b405c..6c1a253c 100644
--- a/src/OpenMesh/Core/Mesh/PolyMeshT.hh
+++ b/src/OpenMesh/Core/Mesh/PolyMeshT.hh
@@ -312,7 +312,7 @@ public:
     {
       return 0;
     }
-    Scalar cos_a = (v0 | v1) / denom;
+    Scalar cos_a = dot(v0 , v1) / denom;
     if (is_boundary(_in_heh))
     {//determine if the boundary sector is concave or convex
       FaceHandle fh(face_handle(opposite_halfedge_handle(_in_heh)));